The proposed studies are designed to identify and study metabolic factors involved in carcinogenesis of the urinary bladder in an attempt to meet the goals of the National Bladder Cancer Project. Comparative host metabolism and activation of biologically foreign arylamine derivatives with known or suspected carcinogenic activity will be investigated in susceptible and non-susceptible species by examining the enzyme-mediated molecular level interaction of these carcinogens with critical cellular macromolecules. The in vivo nitrite-dependent diazotization of naturally occurring urinary arylamines with suspected carcinogenic activity will be examined, as well as the carcinogenic activity of the resulting aryldiazonium ions for the rodent urinary bladder, in an attempt to identify agents that may play a causal role in the genesis of human bladder tumors.